Tony Blair's former advisor John McTernan has told talkRADIO Jeremy Corbyn got it all wrong in his argument with Sir Richard Branson and Virgin Trains - and claims people will now think he's a liar.
Virgin Trains later released CCTV pictures showing there were empty seats available, but Corbyn then tried to close down questions about the issue at a subsequent press conference, and claimed he was looking for two seats together, so he could sit with his wife.
Political commentator McTernan says Corbyn's worst mistake was changing his story about the journey when questioned.
"Branson's got one of the most popular brands in the country, Virgin, and he's got one of the most popular representations of businessmen in the country," he told Sam Delaney. "He's already had bigger fights.
"The worst thing is the incompetence. Tell a lie in politics if you want to, but make sure you're not caught out. If you get caught out, just put your hands up and say sorry, and move on very quickly.
"People will now think Corbyn lied, and it does matter if a leader lies."
Listen to the full interview to find out more